The field of the disclosure relates generally to turbomachinery and, more specifically, to systems for removing heat from turbine components.
In at least some known gas turbine engines, air is pressurized in a compressor and mixed with fuel in a combustor for generating a stream of high-temperature combustion gases. Energy is extracted from the gas stream in a turbine which powers a mechanical load. During operation of the gas turbine engine, various hot gas path components are subjected to the high-temperature gas stream, which can induce wear in the hot gas path components. Generally, higher temperature gases increase performance, efficiency, and power output of the gas turbine engine. Thus, at least some known hot gas path components are cooled to facilitate the gas turbine engine to operate with the increased high-temperature combustion gas streams.
Some known hot gas path components include an airfoil with a cooling system, wherein air, typically bleed air extracted from the compressor, is forced through internal cooling passages defined within the airfoil. The air is then discharged through cooling holes or passages located at an outer surface of the airfoil to transfer heat away from the hot gas path component. This forced air-cooling facilitates the hot gas path components functioning in the high-temperature gas stream. At least some known cooling systems increase a sidewall thickness of the airfoil to increase cooling air flow velocity through the trailing edge to facilitate heat transfer therefrom. However, increasing the sidewall thickness of the airfoil also increases thermal resistance of the surfaces to be cooled. At least some other known cooling systems increase the cooling air flow velocity by extracting additional bleed air from the compressor. However, extracting additional bleed air reduces gas turbine engine efficiency.